Tran, Ngoc Khiem, Thanh Quynh Anh Tran, Tan Dung Nguyen, and Duc Manh Le. 2016. “Studying the Affected Factors to Freeze Drying Process of Natto Preparation”. Journal of Technical Education Science 11 (Special Issue 02):1-10. https://www.jte.edu.vn/index.php/jte/article/view/405.